The Birimian Greenstone Belts of West Africa
July 2013 by Chris RalphThe country we were to visit was Burkina Faso, a small country about the same size of my home state of Nevada with about 10 times more people. The second day I was in Africa, we went out to the goldfields for the first time.
Unfortunately for us mortal humans, we have a poor perspective on geologic time. When we look at a landscape such as a stream valley, we see it only in two, or at the most, three dimensions. We have poor comprehension of the valley’s fourth and most important dimension—time.
From time to time I’ve been doing a series on critical metals and how important they are to our complex and technological society. This month we are going to take a look at copper, and how important that metal is to our modern lives.
It was the middle of winter and the valley was covered in snow, making prospecting a matter of sinking shafts in the ground.
...if you are out prospecting and find something that looks very much like a nugget but has an odd greenish-gray cast to it, don’t be too quick to simply toss it aside as junk.
Every time we prospected here we found gold, sometimes some really coarse flakes, but no large nuggets (yet).
While a large number of locations have yielded some placer gold, most of the state’s placer production has come from a few productive districts.
Gold on the bedrock is a good rule of thumb, but not one that is 100 percent effective. There are plenty of exceptions. So, how does a prospector recognize those exceptions?
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